The invention generally relates to mechanical timing mechanisms and, more particularly, relates to timing mechanisms for shrimp processing machines.
Automated shrimp processing machines are well known. Machines are known which can completely or partially remove the shell of a shrimp, and cut the meat of the shrimp to various depths and at various locations. Examples of such machines are disclosed in U.S. Pat. Nos. 3,159,871; 4,413,377; 4,414,709; 4,439,893; 4,472,858; 4,473,740; 4,507,825; 4,745,660; 4,769,871; 5,035,670; 5,366,405; 5,435,775; and 5,522,764; all of which are assigned to the present assignee.
With specific reference to the aforementioned U.S. Pat. No. 5,522,764, it discloses a cutting assembly which includes a pivotable cutter bar to which a cutting blade is rotatably mounted. The cutter bar pivots relative to a main processing wheel, to the periphery of which are mounted a number of clamping assemblies for holding individual shrimp. As the main wheel or gear rotates, each shrimp moves to a location proximate the cutting assembly whereupon the cutter bar pivots toward the main wheel, with the cutting blade entering the meat of the shrimp. Guides and other mechanisms can be provided to control the depth of each cut.
Depending upon the size of the shrimp being processed, the number of clamping assemblies provided on the main gear, and the desired location of each cut on each shrimp, the timing with which the cutter bar moves towards the main wheel to make each cut may need to be adjusted. With conventional cutting assemblies, such as those disclosed in the aforementioned patents, the timing of the cutting assembly, while adjustable, requires a fair amount of hardware and labor to perform the adjustment operation. More specifically, U.S. Pat. No. 4,472,858, discloses a guide and cutter depth control apparatus wherein a cutter bar includes a cutting blade and cam wheel rotatably mounted thereto. The cam wheel is rotatable by a shaft and associated knob such that a particular cam surface on the wheel can be selected. A threaded stud and yoke assembly are provided to secure the cam wheel in a desired location. Therefore adjustment of the cutter bar requires, among other things, that the threaded yoke and stud be loosened, the adjustment knob be rotated to the desired cam surface and the threaded yoke and stud be re-secured.
In accordance with one aspect of the invention, a cutter assembly for a shrimp processing machine is provided which comprises a pivotable cutter bar, a cutting blade, a rotatable cam wheel, a driven gear and a biasing member. The pivotable cutter bar includes first and second ends. A cutting blade is mounted to the cutter bar. The cam wheel includes a cam surface with the second end of the cutter arm being in engagement with the cam wheel. Engagement of the second end with the cam surface causes the cutter arm to pivot and move the cutting blade. The cam wheel includes an internal aperture with a plurality of internal gear teeth extending radially inwardly from the internal aperture. The driven gear includes a plurality of gear teeth extending radially outwardly from the driven gear. The driven gear teeth are adapted to mesh with the cam wheel gear teeth. The biasing member maintains the cam wheel gear teeth into engagement with the driven gear gear teeth.
In accordance with another aspect of the invention, a method of adjusting cutting blade timing on a shrimp processing machine is provided. The method includes the steps of disengaging gear teeth of a drive gear from the gear teeth of a cam wheel, rotating one of the drive gear and cam wheel relative to the other of the drive gear and cam wheel, and re-engaging the gear teeth of the drive gear with the gear teeth of a cam wheel.
In accordance with another aspect of the invention, a shrimp processing machine is provided which comprises a main drive wheel, a plurality of clamp assemblies on the main drive wheel, a shrimp breaking mechanism proximate the main drive wheel, a meat-picking mechanism proximate the main drive wheel, and a cutter assembly proximate the main drive wheel. The plurality of clamp assemblies are each adapted to hold and release shrimp. The shell breaking mechanism is adapted to break shrimp shells, while the meat picking mechanism is adapted to pull meat from the shrimp shells. The cutting assembly is adapted to cut the meat of each shrimp at timed intervals. The timing of the intervals is adjustable by a toothed adjustment mechanism.
These and other aspects and features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.